Nitrogen Deposition Effects of Ammonia Ammonia Workshop



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Nitrogen Deposition Effects of Ammonia

  • Ammonia Workshop

  • National Atmospheric Deposition Program

  • October 22-24, 2003

  • Washington, DC

  • USA


Contrasting NOx and NH3

  • Historical focus on NOx

  • Growing focus on NH3

  • Similarities

    • Both have point and mobile sources
    • Both, once emitted can be converted to any other N species
  • Both contribute to all the N-related impacts.



Reactive N vs Unreactive N2

  • Unreactive N is N2 (78% of earth’s atmosphere)

  • Reactive N (Nr) includes all biologically, chemically and physically active N compounds in the atmosphere and biosphere of the Earth

  • N controls productivity of most natural ecosystems



Reactive N vs Unreactive N2

  • Unreactive N is N2 (78% of earth’s atmosphere)

  • Reactive N (Nr) includes all biologically, chemically and physically active N compounds in the atmosphere and biosphere of the Earth

  • N controls productivity of most natural ecosystems

  • Nature converts N2 to Nr by biological nitrogen fixation (BNF).

  • Humans convert N2 to Nr by fossil fuel combustion, the Haber Bosch process, and cultivation-induced BNF.



Reactive N vs Unreactive N2

  • Unreactive N is N2 (78% of earth’s atmosphere)

  • Reactive N (Nr) includes all biologically, chemically and physically active N compounds in the atmosphere and biosphere of the Earth

  • N controls productivity of most natural ecosystems

  • Nature converts N2 to Nr by biological nitrogen fixation (BNF)

  • Humans convert N2 to Nr by fossil fuel combustion, the Haber Bosch process, and cultivation-induced BNF.

  • Primary Conclusions

    • Humans create more Nr than do natural terrestrial processes.
    • Nr is accumulating in the environment.
    • Nr accumulation contributes to most environment issues of the day.
    • NHx and its conversion products are key components.


Objectives

  • Contrasting NOx and NH3

  • Human Alteration of N Cycle

    • An agrarian to an industrializing world
  • The Consequences of Anthropogenic Nitrogen (including NH3).

    • Nitrogen is nutritious
    • Nitrogen cascades
  • Challenges!



The History of Nitrogen --N becomes limiting?--



The History of Nitrogen --N becomes limiting?--





The History of Nitrogen --Nr Creation, Haber Bosch process--



The History of Nitrogen --Nr Creation: Fossil Fuel Combustion--



The History of Nitrogen --Nr Creation, People and Nature--



Nitrogen Drivers in 1860





Nitrogen Drivers in 1860 & 1995





Nitrogen Deposition Past and Present mg N/m2/yr



Nr and Agricultural Ecosystems

  • Haber-Bosch has facilitated agricultural intensification

  • 40% of world’s population is alive because of it

  • An additional 3 billion people by 2050 will be sustained by it

  • Most N that enters agroecosystems is released to the environment.



Nr and the Atmosphere

  • NOx emissions contribute to OH, which defines the oxidizing capacity of the atmosphere

  • NOx emissions are responsible for tens of thousands of excess-deaths per year in the United States

  • O3 and N2O contribute to atmospheric warming

  • N2O emissions contribute to stratospheric O3 depletion



Nr and Terrestrial Ecosystems

  • N is the limiting nutrient in most temperate and polar ecosystems

  • Nr deposition increases and then decreases forest and grassland productivity

  • Nr additions probably decrease biodiversity across the entire range of deposition



Nr and Freshwater Ecosystems

  • Surface water acidification

    • Tens of thousands of lakes and streams
    • Biodiversity losses
  • As reductions in SO2 emissions continue, Nr deposition becomes more important.



Nr and Coastal Ecosystems

















Hog Production in USA (1 dot= 10,000 Hogs and Pigs)



Meat Consumption in North America (kg/capita/year)



Conclusions

  • NH3 contributes to every N-related issue

    • Directly or indirectly
  • Nr and NHx are accumulating in environmental reservoirs

  • The impacts of N accumulation are significant and inter-related

  • NH3 emissions will increase with time

  • There is need for an integrated approach to manage N!



Meat Consumption in North America (kg/capita/year)





Nr Creation Rates by Food and Energy Production in 2050



Nr Creation Rates 1995 (left) and 2050 (right) TgN/yr



Nr Creation Rates 1995 (left) and 2050 (right) TgN/yr



The Fate of Haber-Bosch Nitrogen



The Fate of Haber-Bosch Nitrogen



The Fate of Haber-Bosch Nitrogen



The Fate of Haber-Bosch Nitrogen



Nr Riverine Fluxes 1860 (left) and 1990 (right) TgN/yr



Nr Formation vs. Nr Conversion back to N2



Nr Formation vs. Nr Conversion back to N2



Nr Formation vs. Nr Conversion back to N2



International Nitrogen Initiative

  • Formed in December 2002; SCOPE & IGBP sponsors

  • Objective

    • optimize nitrogen’s beneficial role in sustainable food production and minimize nitrogen’s negative effects on human health and the environment resulting from food and energy production.
  • Preliminary assessment in December 2004.





The Components of INI



The Components of INI



Phase I: Assessment of Science and Identification of Problems



Phase I: Assessment of Science and Identification of Problems



Phase I: Assessment of Science and Identification of Problems



Phase I: Assessment of Science and Identification of Problems



Phase I: Assessment of Science and Identification of Problems



Phase II: Development of Solutions Phase III: Implementation of Solutions



International Nitrogen Initiative Current Status

      • Formed in December 2002
      • Sponsored by SCOPE and IGBP
      • INI has a 15-person Scientific Advisory Committee
        • members from Brazil, China, France, Netherlands, Japan, South Africa, Sweden, Thailand,Uganda, United Kingdom, United States
      • First SAC meeting is hosted by Dutch Government
        • May 12-14, 2003, The Hague


The Challenge to all Parties

  • Maximize food and energy production while maintaining environmental and human health!



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